• Biomolecules & Therapeutics
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• 제26권3호
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• pp.306-312
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• 2018

In a previous study, we have demonstrated that S-methylmethionine sulfonium (SMMS) confers wound-healing and photoprotective effects on the skin, suggesting that SMMS can be used as a cosmetic raw material. However, it has an unpleasant odor. Therefore, in the present study, we synthesized odor-free SMMS derivatives by eliminating dimethyl sulfide, which is the cause of the unpleasant odor and identified two derivatives that exhibited skin-protective effects: one derivative comprised (2S,4S)- and (2R,4S)-2-phenylthiazolidine-4-carboxylic acid and the other comprised (2S,4R)-, (2S,4S)-, (2R,4R)-, and (2R,4S)-2-phenyl-1,3-thiazinane-4-carboxylic acid. We performed in vitro proliferation assays using human dermal fibroblasts (hDFs) and an immortalized human keratinocyte cell line (HaCaT). The two SMMS derivatives were shown to increase hDF and HaCaT cell proliferation as well as improve their survival by protecting against ultraviolet exposure. Moreover, the derivatives regulated the expression of collagen type I and MMP mRNAs against ultraviolet exposure in hDFs, suggesting that these derivatives can be developed as cosmetic raw materials.

• 한국통신학회논문지
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• 제21권8호
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• pp.2077-2089
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• 1996

In this paper, a memory organization and its control method are proposed for the implementation of parallel Virterbi decoders. The design is mainly focused on lowering the hardware complexity of a parallel Viterbi decoder which is to reduce the decoding speed. The memories requeired in a Viterbi decoder are the SMM(State Metric Memory) and the TBM(Traceback Memory);the SMM for storing the path metrics of states and the TBM for storing the survial path information. A general parallel Viterbi decoder for high datarate usually consists of multiple ACS (Add-Compare-Select) units and their corresponding memeory modules.for parallel ACS units, SMMs and TBMs are partitioned into smaller independent pairs of memory modules which are separately interleaved to provide the maximum processing speed. In this design SMMs are controlled with addrss generators which can simultaneously compute addresses of the new path metrics. A bit shuffle technique is employed to provide a parallel access to the TBMs to store the survivor path informations from multiple ACS modules.

• 한국측량학회지
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• 제26권1호
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• pp.85-91
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• 2008

수평조정망과 같이 커다란 희소행렬(sparse matrix)을 계산할 때, 시간적 효율 및 공간적 효율을 높이기 위해서 재배열(reordering) 과정을 거치게 된다. 본 연구에서는 SMMS(Sparse Matrix Manip ulation System) 프로그램을 이용해서 희소행렬의 원소를 각각의 재배열 방법으로 재배열 한 후, 전체 계산에 걸리는 시간과 치환배열을 구해 해를 구하는 과정시 발생하는 Fill-in의 개수를 계산해서 각 방법의 효율성을 비교하였다. 그 결과, Minimum Bandwidth 기반의 GPS(Gibbs-Poole-Stockmeyer), RCM(Reverse Cuthill-Mckee) 방법보다 최소 차수(Minimum Degree) 기반의 MD(Minimum Degree), MMD(Mutiple Minimum Degree) 방법이 더 효율적인 모습을 보여주었다. 하지만, 행렬의 원소 분포에 따라서 최적의 성능을 보이는 재배열 방법은 달라질 수 있다는 것을 알 수 있었다. 이러한 연구 결과는 향후 전국 기준점의 좌표값 재조정 시, 또는 대규모 측지망 조정 등에서 구성 요소 계산에 필요한 시간, 저장 공간 등의 효율을 높일 수 있는 효과를 기대할 수 있을 것이라 사료된다.

• Educational Technology International
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• 제10권2호
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• pp.63-83
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• 2009

The purpose of this study was to investigate the cognitive mechanism of e-Learning contents development projects on the basis of the Shared Mental Model theory perspective. To pursue the purpose, a theoretical model and several hypotheses were developed based on relevant literature. Thirty five (35) e-Learning contents development teams composed of 202 instructional designers from for-profit professional e-Learning companies in Korea were participated in this study. For the analyses of the fit of the Model and parameter estimations, Structural Equation Modeling (SEM) method was employed. As hypothesized, e-Learning contents development team members' interaction leads to higher SMMs which in turn facilitate member satisfaction within the team. Meanwhile, the frequency of interaction among team members decreases as projects progress.

• 멤브레인
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• 제18권3호
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• pp.206-213
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• 2008

폴리비닐리덴풀루오라이드(Poly vinylidene fluoride, PVDF) 막을 고분자(Surface Modifying Macromolecules, SMM) 첨가제를 사용하여 표면 개질 하였다. 표면 개질된 PVDF 막의 제조는 0에서부터 2 wt%까지 SMM의 다양한 농도로 제조되었으며, 사용된 SMM으로써는 Zonyl BA-L을 이용하였다. 제조된 막을 이용하여 주사 전자 현미경법(SEM)과 접촉각 측정(Contact angle)을 하였고, 투과증발(Pervaporation)공정을 이용하여 물-에탄올 계의 분리실험을 통해 특성 평가를 하였다. 그 결과 SEM image를 통하여 SMM이 PVDF막 표면에 층을 형성하였음을 알 수 있었고, 접촉각은 기존의 PVDF 막 보다 SMM을 2 wt% 첨가하였을 때 $8^{\circ}$ 증가한 것으로 보아 소수성이 증가한 것을 알 수 있었다. 또한 물-에탄올 계에 대한 투과증발 실험은 다양한 조업온도별(50, 60, $70^{\circ}C$)로 수행하였으며, Zonyl의 함량이 PVDF 대비 1, 2 wt% 함유된 막을 사용하였으며 원액의 조성은 무게비로 물 10, 20, 50, 100%에 대하여 조사하였다. 물 : 에탄을 = 10 : 90 조성, 조업온도 $50^{\circ}C$에서 선택도 287과 투과도 5.3 $g/m^2hr$를 PVDF/2 wt% Zonyl BA-L 막이 보여주었다.

• 한국경영과학회지
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• 제34권2호
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• pp.1-13
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• 2009

In this paper, we develop theoretical game models to determine the level of government subsidies for banks to provide policy loans to Innovative SMEs(small and medium sized enterprises) through banks, which otherwise would not finance them for the sake of their own profitability. For this, we compare net cash flows of each bank using different strategies against high risk innovative SMEs. A bank can decide whether to provide them loans or not In each period. Following Kim(2003)'s Infinite horizon model on the soft budget constraint, we introduce a situation in which banks compete against each other for higher net long-term payoffs from their loans to innovative SMEs and non-innovative SMEs. From the models, we show that competition among banks in general leads to a tighter decision against innovative SMEs, as a Nash equilibrium. It is not because the government bank is simply loose in providing loans, but because competition among commercial banks for fewer riskier borrowers results in tighter loan decisions against innovative SMEs. Thus, the competitive market for policy loans to innovative SMEs fails to reach the socially optimal level of loans for innovative SMMs. Commercial banks in the competitive market may require additional supports from the government to make up for the differences in their payoffs to support innovative SMEs, possibly much riskier due to moral hazards and poor discounted cash flows. The monopolistic government bank might also request such supports from the government to fund otherwise unqualified SMEs. We calculate an optimal level of governmental support for banks to guarantee funding such high-risk innovative SMEs over periods without deviating from their optimal Nash equilibrium policies.

• 한국콘텐츠학회논문지
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• 제17권8호
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• pp.366-381
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• 2017

본 연구의 목적은 질분만을 한 여성의 만족을 측정하기 위해 질분만만족 측정도구를 한국어로 번안하고 한국형 질분만만족 측정도구의 타당도와 신뢰도를 평가하는 것이다. 한국형 질분만만족 측정도구는 205명의 산모를 대상으로 평가하였고, 준거타당도를 평가하기 위해 분만경험지각을 측정하였다. 탐색적 요인분석결과 6요인, 23문항으로 나타났다. 확인적 요인분석결과 좋은 수렴타당도와 판별타당도를 보였고, 요인간 상관관계는 0.11~0.57이었다. 한국형 질분만만족 측정도구는 분만경험지각 측정도구와 좋은 동시타당도를 나타냈다. 전체 문항의 내적일관성 신뢰도인 Cronbach alpha는 .91, 하부요인은 .80에서 .90 사이였다. 따라서 한국형 질분만만족 측정도구는 신뢰도와 타당도가 검정된 도구이므로 산후 2, 3일째 병원에서 산모의 질분만만족 평가에 사용할 수 있다.